<SEC-DOCUMENT>0001127602-23-027104.txt : 20231109
<SEC-HEADER>0001127602-23-027104.hdr.sgml : 20231109
<ACCEPTANCE-DATETIME>20231109163527
ACCESSION NUMBER:		0001127602-23-027104
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20231108
FILED AS OF DATE:		20231109
DATE AS OF CHANGE:		20231109

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DEBENEDICTIS NICHOLAS
		CENTRAL INDEX KEY:			0001194707

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34481
		FILM NUMBER:		231393189

	MAIL ADDRESS:	
		STREET 1:		GLATFELTER
		STREET 2:		96 SOUTH GEORGE ST STE 420
		CITY:			YORK
		STATE:			PA
		ZIP:			17401

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Mistras Group, Inc.
		CENTRAL INDEX KEY:			0001436126
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
		IRS NUMBER:				223341267
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
		BUSINESS PHONE:		609-716-4000

	MAIL ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2023-11-08</periodOfReport>

    <issuer>
        <issuerCik>0001436126</issuerCik>
        <issuerName>Mistras Group, Inc.</issuerName>
        <issuerTradingSymbol>MG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194707</rptOwnerCik>
            <rptOwnerName>DEBENEDICTIS NICHOLAS</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MISTRAS GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>195 CLARKSVILLE</rptOwnerStreet2>
            <rptOwnerCity>PRINCETON JUNCTION</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08550</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>25000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-11-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3684</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.94</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>190427</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2023-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>120</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>186743</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price on this line represents the weighted average price for the transactions reported on this line. The range of prices for the transactions reported on this line was $5.82 to $5.96. Upon request by the Commission staff or a security holder of the issuer, the full information regarding the number of shares purchased at each separate price shall be provided. The information has been provided to the issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Michael C. Keefe. attorney-in-fact for Nicholas DeBenedictis</signatureName>
        <signatureDate>2023-11-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
